Telephone-exchange.



I PATENTED JULY 2, 1907. C. AQANDBRSON. TELEPHONE EXCHANGE.

A PPLIOATION FILED MAY 18.1903.

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No. 858,363. I PATENTED-JULY2,1907.

' 0. A. ANDERSON.

TELEPHONE EXCHANGE APPLICATION FILED MAY 18.1903.

e SHEETS-SHEET 2.

N'o. 858.363. I PATENTEDJULY 2', 1907.

' 0.- A. ANDERSON.

"TELEPHONE EXCHANGE.

APPLICATION FILED MAY 18,1903.

' 6 SHEETS-SHEET .3.

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mmllll mllilill Np. 858,363. r PATENTED JULY 2, 1907.

- G. A ANDERSON.

TELEPHONE EXCHANGE.

APPLICATION FILED MAY 18.1903.

6 SHEETS-SHEET 4.

PATENTEDJULY, 2, 1907.

0. A. ANDERSON. TELEPHONE EXCHANGE.

APPLICATION FILED MAY 18,1903.

6 BHEETS-SHEET 5.

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No. 858.363. I PATENTED JULY 2, 1907.

' G. A ANDERSON.

TELEPHONE EXCHANGE.

. APPLICATION FILED MAY 18,1903. E

v 6 SHEETS-SHEET 6.

' witnesses: I I E iiunemnr fl zi; g2 4/; sd- QW C PATENT OFFICE.

CLARENCE A. ANDERSON, 01" LINDSBORG, KANSAS.

TELEPHONE-EXCHANGE.

' zen of the United States of America, and a resident of magnets M and M.

Lindsborg, county of McPherson, and State of Kansas, have invented certain new and useful Improvements in Telephone-Exchanges, of which the following is a specification.

My invention relates to telephone exchanges and has for its object certain improvements in party line exchanges.

My invention' is illustrated in the accompanying drawings in which Figure 1 is a front elevation of the switching mechanism used at each local station; Fig. 2 is a side elevation of the same; Fig. 3 is a plan; Fig.4 is a face view of the contact supporting table traversed by the contact maker; Fig. 4" is a modification of one of the contacts shown in Fig. 4. Fig. 5 is an edge view of Fig. 4; Fig. 6 is a section on line 6-6 of Fig. 4; Figs. 7 and 8 are respectively elevation and section of the yielding supports under the armature lever of the operating magnets; Fig. 9 is an elevation of the front face of a calling box at the central ollice; Fig. 10 is an inside view of the box cover and the mechanism supported thereon; and Figs. 11 and 12, taken together, are a diagram showing the central ollice and three local stations connected tea party line.

In the said drawings A is a plate upon one side of which is supported a switching mechanism and upon the other side of which is a direct current generator G. The switching mechanism consists of a ratchet wheel B operated by a pawl ll on a lever B. The lever B is secured to an armature l? which is movable in either direction from its central or normal position by the of set screws G the magnets M and M are held at any desired vertical adjustment. The result of this construction is that the lower ends of the magnets M and M are of the same polarity as that of the permanent magnet at the point of attachment of the br acket G. In a similar manner the bracket G is magnetically connected to the 'other pole of the generator G through the bracket G. To the bracket G is pivoted the armature 13, which armature has a polarity opposite to that oi the adjacent ends of the magnets M and M.

Secured to the bracket G6 aro'two short tubes B which maybe held at any desired vertical adjustment by means of nuts B The upper end of thetube B is closed by a plug 13 and the lower end is closed by an Specification of Letters Patent.

Application filed May 18, 1903, Serial No. 157,598-

Patented. July 2,1907.

adjusting screw 13. Inside of the tube B, and passing through holes in B and B is a rod 13 which is held in its upper position by a spring B. The upper ends of the rods B touch the lower face of the armature B and serve to hold the said armature in its mid position at equal distances from the poles of the magnets M and M. By means of thescrew adjustment of the tubes B the upper ends of the rods B may be vertically adjusted so as to bring the armature B to its required mid-position. By means of the adjustment of the screws 13 the tension of the springs B may be varied.

Supported at a convenient place on the plate A are two insulated springs and 61, the ends of which project adjacent, to one end of the armature B These springs are not normally in contact with each other but they are so arranged that when the armature B is at- (tracted by the magnet M they will be brought into electrical connection. Attracting the armature B by the magnet M does not affect the springs 60 and 6]..

Supported in any convenient manner is a pin B one end of which projects under the pawl B. When the magnet M attracts the armature B the pawl B engages the teeth of the ratchet wheel B'and moves the said wheel forward one step. When the armature B returns to its mid-position the said pawl engages the next tooth of said wheel and rests closely adjacent to the pin B. When the armature B is attracted by the magnet M the pawl B rides over the pin B and is lifted out of engagement with the teeth of the wheel B.

Secured to the ratchet wheel B is along and flexible contact maker P which sweeps over a certain space when the wheel. 13 is moved. Lying in the path of the contact maker P are two plates of insulating material C and O, and between those is a metal plate 90. The plate C is removed from the plate 90 a suflicient (listanco to permit the contact maker P to pass between them. Through the plate 0 is an opening or notch 0 arranged to permit the contact maker P to pass from the upper face of C to contact with the metal plate 90.

Adjacent to the plates 0 and C is a long and flexible spring 29, the free end of which lies adjacent to one end of the plates .0 and C and rises to a position slightly above the upper face of C. In its normal position the contact maker P lies-closely adjacent to the end of the plate 0 and is held by the spring29 slightly above that plate. When thecontact maker P is advanced by a movement of the ratchet wheel 13 it moves 0H of the spring 29 and on the upper face of the plate (1, over which it passes as the wheel moves forward. When the contact maker P reaches the opening C it drops off of the plate 0 into contact with the plate90. If, when in this position,-the ratchet wheel B be returned to its normal positionpthe contact maker willpass between the lates (l and 90, remaining in electrical contact with 90 P v during this return movement. Just before the contact maker P reaches its normal position it passes the end of the plate 0 and is free to be raised by the spring 29 to a position above the face of the plate 0. The spring 29 is flexible enough to freely yield to the contact maker P when held down by {the plate 0, but the contact maker is still more flexible, and hence is easily raised by the spring 29 when no longer held down by the plate 0. On the upper'face of the plate 0 is a contact strip or point 57 which is connected by a wire to a magnet M hereinafter to be described. In the switching mechanisms of the different stations this contact point is at different distances from the normal position of the contact maker P. For example, at station No. 1 it would. be one step of the ratchet wheel 13 from the normal position of For station No. 2 it wouldbe two steps, and so on. Also on the plate 0 is a second contact strip or point 65 which is provided with an electrical connection hereinafter, to be described. The contact 65 lies closely adjacent to the opening and is at the last position that the contact maker P occupies before it drops into connection with the plate 90. Also on the plate A is a magnet M provided with an armature E, one end of which armature is marked 79. Adjacent to the magnet M are three insulated contact springs 67, 68 and 78. When the armature E is actuated by the magnet M 79 makes electrical connection with 78, and also push es 68 into electrical connection with 67. When the armature is retracted these electrical connections are broken. Also, on the plate A is a magnet M provided with anarmature F which has a hook F. When the magnet M attracts its armature E, said armature is caught by the hook F and held in its attracted position, which position holds contacts between 78 and 79, and between I 67 and 68. When the armature I, is attracted by the magnet M, E is released from F and the electrical contacts are broken.

Supported at a suitable place is a holding pawll for the ratchet wheel- B, which pawl has a tail piece F that lies adjacent to an extension F on the armature F. When the ratchet wheel B is advanced by the pawl B this advance is held by the pawl F When the armature F is attracted by the magnet M the extension F strikes the tail piece F and lifts the pawl F out of engagement with the ratchet wheel. If the magnet M operates simultaneously with the magnet M then the pawl B will ride over the pin B and also release the wheel B so that it may be returned to normal position. This return is effected by a spring wrapped around the spindle of the wheel and shown at B in Fig. 2.

At the central office there isa box Shaving on its lront face a crank S a numbered dial 8", and a pointer 64 for the dial. In the'dial, and in the path of. the pointer 64, are a series of holes S in which may be inserted pins. holes and the pointerniovcd, the said pointer will touch thepin in passing and make an electrical connection therewith and consequently with the dial. li several pins are placed in the holes, then the pointer will make a corresponding number or contacts.

On the inside of the cover of the box S is a goal-S" which is connected to the spindle ol' the crank S. The gear S meshes with another gear S" to which is secured a star wheel S. This star wheel has as many points as there are numbers on the dial S livotcd on tluinside of the cover of the box S is a lever J, the [rec end of When a pin is inserted injonc oi these I which is arranged to enter the spaces between the points of the star wheel S: A spring J holds the lever J against the star wheel but permits the said lever to vibrate when the star wheel is rotated as aresult of turning the crank S.

On a convenient part of the lover I is a projection 43 having a piece of insulation secured to one side of it. 'When the lever .l' is in its normal position-this piece of insulation strikesa spring 54 and presses it into electrical connection with another spring 55. When the lever is moved outward by the rotation of the star wheel 8 the electrical connection between these springs is broken. Located adjacent to the projection 43 :1re three insulated springs 42, 48 and 49. Those springs are normally separated from each other and from the projection 43, but "when the lever J is moved outward 43 makes an electrical connection with 42, and also pushes 48 into electrical connection with 49.

In arranging a telephone exchange I provide a central oflice from which one or more party lines may extend. Assuming one party line, I provide a calling box like the one described, a telephone set including receiver R, induction coil K, battery X, plugs V and W, spring jacks V and W drop D, clearing out drop D and certain keys and connections as shown in the diagram. The diagram also shows a direct current generator G which may or may not be used as desired.

At each local station there is a switching mechanism like that described, a r eiver-1t, hook l'I, induction coil K, bell ringing device Q, direct current generator G, and electrical connections as shown. The central office is connected to the local stations by a wire 27 having branches to each station, and by a ground connection. There are no other connections between the several stations, and it is one of my principal objecls to provide a satisfactorily working exchange of the party line type which will have its connections rcduced to one wire and ground connections.

Assuming that the subscriber at telephone station No. 1 Wishes to talk to the subscriber at telephone station No. 3 he will proceed as follows: I'Ic first turns the crank of his generator G when a direct current flows as follows: G-20- 2l22--' ground to the central ofiicc 2324l) 25-26--27 back to station No. 128-P-2)--30--31-3233-G. This operates the drop D and calls the operator at the central oflice who inserts the plug V in the jack V and presses the key L.

The subscriber removes his receiver R when the nuking circuit is as follows: K at station No. l 34 ll- 35'36'29P--28-27 to the central oiilce .-2G-V 3738-L-39R40K23--' ground back to station to No. 122Il 'K. The subscriber tells the central olilce that he wishes to talk to station No. 3 where- 23--ground to all of the lm-nl-slations --22- 15-' M- M -16 -28 I 27-- back to the central oilico2(i-V- :5? -l7 "l8 -19-- 50- 51 -51 'lhemagnots M and .\l are so wound that this current through them acts to increase the magnetic force oi M and decrease that of M the result of which is the advance of the 'ratchet wheels of the dillcrcnt stations and the consequent movement of the contact makers I from connection with the spring 29 to the plate C. This is repeated for each point on the star wheel S, the number of which, by the preliminary movement, is sufli'cient to leave all of the contact makers on their contacts points 65.

When the pointer 64 strikes a pin in the dial 8*, which I in this case is in the Iirst hole and while the projection 4-8 closes the connection between 54 and 55, then the current llows as fol lows: X-4l.----53--5 1---55-56-'47- 37-V--2(i- 27-- to all stations -28-- li -M: -hl 22- ground back to the central ollice '23-44-63- 6451-52X. This is a current in the opposite direction through these magnets and consequently results in moving their armatures in the opposite direction. The only effect of this is to close (30 to (it. As this occurs when the pointer 6 1 is at the first hole in the dial 8, the contact maker P of the station No. 1 will be the only one in connection with its contact point 57, consequently at this station a branch of the previously described current will go fronr28 5758-M-- fore described. The result of this branch is to actuate M. and close 79 to 78, also to close 68 to 67, these connections being made for ringing and talking at the station at which they occur. The same operations are repeated at station No. 3 which is the only station having its contact maker P on its contact point 57 at the time the pointer ti l touches the pili placed in"the third hole of dial 6. The same thing would occur for any other stations on the party line provided contact pins had been placed in other holes in the dial 8*.

With the contact makers l on the contact points the operator presses the key N when a current ilows as follows: X- --l.l---53-" 5" "55""56"47- 37-V"izll 27 7l. II---22--- ground back to the central ollice -23- A4 --72 7il-- N--- 5'l.-52--X. This operates the ringing device at station No. 3 and calls the sul. scriber. It would also operate the ringing device at station No. 1 provided the subsciiber at that station had returned his receiver to its hook. it would not operate the ringing devices at other stations because their magnets l\1-' had not been previously operated and consequently there would be no connection between ($7 and (58. There is a branch of this ringing circuit that goes from 28 through the magnets M and M, but as the direction of the current going over this branch is contrary to the operating direction it is without effect. Instead of rising the battery for ringing the operator may accomplish the same result by pressing key N and turning the crank of generator G when a current flows as l'ollows: G--74--75-- '7(S--N" -"1,S- --I-l7-- I as before to ground --2I- l l- --77-G.

With both receivers ol'f oi their hooks the talking circuit between stations is as l'ollows;' K. at station No. I|.- 34 ---R-35--78-7!J-8o--27 to station No. 3 797835-R34-Kll-22:- ground back to sta tion N0. '1--22-ll-K.

As soon as the central operator places the stations in connection with each other sh'e inserts the plug W in the spring jack W, then, when the subscribers are through in] king, they ring off as follows: -(l --2U---2'l W 22 ground --23 5l----W-' sz- 1)'-:i7 --v -'2t 27 SU' -7i)--78---3536-BU-+3 l---32--33-(.i This notiit also closes (ll) to 61 when a branch ol' the circuit just described goes from 28 to l-.9ll-i\l--5t)-- [SU GL- 62 -21-22- at which point it joins the previous current. This last action attracts the armature of M, releases the arrnature oi MI, and lifts the holding pawl from the ratchet wheel. As this occurs while the driving pawl is also lifted it leaves the ratchet wheel free to be returned to its norn'ial position. During this return movement the connection is held through the magnet M until the contact maker runs off of the end oi the contact plate and is lifted to its original position by the spring 29. v k

The calling device is shown with a dial having twelve holes and a star wheel having twelve points. In this casethe limit of the number of stations on the party line would be ten. By increasing the holes in thedial and the number of points on the star wheel any desired number of stations may be placed on the line. When the limit of the exchzipgc is two less than the number of points on the star wheel the contact 57 of the last station will be closely adjacent to the contact 65. Although I have shown and described an exchange particularly arranged for twostations less than the nu mber of points on the star wheel, I can advantageously make the number of points on the star wheel three or four more than the number of stations. When I do this I lengthen out the contact point 65 (as'shown in Fig. 4) so that it will be in contact with P for two or three steps of the ratchet wheel. The contact plate 90 is also lengthened out so that P may move on it for two or three steps after passing from (35. The object of this is to compensate for misses in the operation by which one switch falls one or two stcps bchind the others. Thus suppose. (if) be lcuglhcncd out loan cxlcnt equal to tllrcc steps of the contact maker, that the operator stops the initial movement of the poiutcr (34- three steps short of a complete rotation, and that this would. leave the contact. makers P on the contact. points (if) closc to the edge ol' the opcning Then if one of the switching mechanisms had missed one or two steps in its forward nmvcmont it would still have its contact.

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. I- v maker on its contact point o5. Upon the completion plished by lcllgthcnillg the contact plate 90 and the relurn of the mechanisms to their normal positiori. The magnets on the switching mechanisms are wound so that the different branches will have like resistances,.thc object of which is to prevent a branched circuit carrying more current over one branch than over the simultaneously operated branch.

The switching mechanisms are bridged across the line, which line consists oi one Wire and ground. It will be observed that the switching mechanisms are in complete control of the central oiliee and that their op erations are independent of anything, that the subscribers may do. Also that the subscribers can not break into a' line in use. As switching mechanisms at the local stations are usually inclosed in boxes this impossibility of the subscribers breaking into a talking circuit will be evidcnt irom the fact that removing his receiver and turning his generator crank are the only operations that he performs. li a subscriber not called removes his receiver when the line is in use he will find his connections broken between 78 and 7 9 because the magnets M' have been operated only at the stations called. if he should turn his generator crank when the line is in use he would i ind it Without effect because the current from the generator passes through P and 29 and the connection between these two is broken by the first movement oi the switching mechanism anterior to placing the line in use.

What I claim is:

1. The combination with a switching mechanism, means for advancing it step by step from its normal position, and electrical devices for releasing it. so that it may return to its normal position, of a Contact. maker carried by said switching mechanism and arranged to close electrical connection for said electrical devices at a point in the latter part 01 the forward movement of said mechanism, and means by which said contact is held c'losed (luring two or i v t more steps 01 the iorward movementoi said mechanism.

2. The combination with step by step mechanism, a propelling device therefor, and a holding pawl, of a mag net for releasing said mechanism from its holding pawl. and a normally open electrical connection for said magnet arranged to be closed by the forward movement of said meclmnisin and to be held during two or more steps thereof.

.l. [lhecomhination with a switching mechanism, a pro polling device therefor, 21. holding pawl, a magnet for re-.

- to said magnet.

4. The combination with a switching mechanism, means for advancing it from its normal position, and electrical devices for releasingit, 01' an electrical connection for said electrical devices closed by the latter part: of the advance movement: of soidnrec lmnism, and means by which such connection is. held closed during two or more advance steps of said 'mechanisin.

in a telephone exchange, a control oiiice, and a series e11 local stations connected together by a party line, a calling (lcvicclocai'ed at the central oilice and provided with a numbered dial and a pointer therefor. a switching mechanism :ii: ear-h station, means whereby upon moving said pointer i'ora predetermined distance less than a complete rotation said mechanisms will be moved to connect selected stations l'elephonically to the party line, and means where by upon completing the'roiaiion of said pointer" said mechanisms will be moved to a position from which they may bereturne'd to their normal positions.

6. In a telephone exchange consisting of a central oiiice and a series of local stations connected by a party line, a cont-act maker at each station and means for moving, it" to and from its normal position, means whereby each con tact maker in moving in one direction engages two contact points and in moving in the opposite direction engages a third contact point, and means for controlling the movements of said contact: makers from the central oilicc.

7. The combination with a party line, :1 series of local stations, and u switching mechanism at each station, of means for simultaneously advancing the mechanisms step by step, a releasingdevice for each mechanism, means by which all of said mechanisms close electrical connections for their relcasini, devices at the same number oi advance steps from their normal positions, and means by which such electrical connections are held closed for two or more advance steps whereby the accidental displacement of one 01 said mechanisms may be remedied so ilmi all are simultaneously .in position to be released.

R. The. combination with a telephone station, and a switching mechanism, of a magnet and uv centrally pivoted armature so arranged that the armature will he moved in either direction on its pivot according to the direction of the impulsesscnt through the magnet, means by which a movement or the armature in one direction operates said switching mechanism, means by which reverse movements of the armature serve both to place the station in a telephonic conneciion and to release the switching mechanism,

and means hy which the position of the switching mcch-- anism controls the effect produced by any given reverse movement.

9. The combination with a party line, a series of local stations, a switching mechanism at each station, and a magnet for each switching mechanism, of means by which impulscs; in one divcction through said magnet serve to cbnlrol the selective operation oi said mechanisms, ndditionul means by which impulses in the reverse direction pulses in one direction through said magnet serve to coin trol the advance of said mechanism, means by which impulses in the reverse direction through said mnguci serve. to control both the telephonic connection of the station and the release oi the mechanism, and means by which the effective resuli's of such reverse impulses are coiiirollcd by the advance position of said mechanism.

11. The combination with a telephone station, a swiiclling mechanism, and a magnet, of means by which the advance position of the switching; mechanism is controlled by the operation of said magnet in one direction, and means by which the telephonic connection of the station and the release of the switching mechanism are jointly controlled by the advance positions of the switching mechanism and the reverse operation of said magnet.

1' I 'ihe combination with a telephone station. a switcln ing mechanism, and a magnet provided with an armature movable in either oi? two directions according to the (lireciion of impulses flowing through said .magnol, oi in runs by which a movement of the armature in one direction controls the advance movement 01' the switching mcchanism, means by which the revprse movement of the urinaturc controls the telephonic connection of the station when the switching mechanism is at one advanced position, and means by which a similar reverse movement oi. the armature controls the release of the mechanism when the mechanism isv at a diil'crent advanced position.

Signed at liindsborg Kansas this 11th day of May i003.

Clnilthh il l A. ANDERSON.

A. i i. A .mmns. CARI. L. lionn. 

